NF-kappaB activation inhibitors, and their pharmaceutical uses

ABSTRACT

Compounds inhibiting the activation of the nuclear factor κB (NF-κB) are used for the preparation of medications adapted for the treatment of malignant hemopathies and solid tumors, and for the prevention of the appearance or the treatment, of phenomena of resistance to cytotoxic molecules used in the scope of treatment of the above pathologies, appearing in patients treated with these molecules when the latter are adapted to activate NF-κB.

CROSS REFERENCE TO RELATED APPLICATIONS

This application is a division of co-pending application Ser. No.09/856,796, filed on May 25, 2001, the entire contents of which arehereby incorporated by reference.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention has for its object the use of biologicalinhibitors of NF-κB, in the field of treating cancers, and moreparticularly malignant hemopathies or solid tumors.

2. Description of Related Art

Numerous tumoral cells have developed sophisticated mechanismspermitting them to resist the effect of certain agents used inanti-cancer chemotherapy. One of the counter-measures at presentdeveloped by clinicians is the increase of the dosage of thesemedications, with the result of aggravating the side effects observed inthe patients. Thus, for example, most of the leukemias and certainlymphomas are treated by the administration of anthracyclines(daunomycin, dauxorubicin) whose toxicity is manifest in the vitalfunctions (hepatic, cardiac . . . ) (Gauthier, P H, 1987, Gas Med Fr,94:43-49).

The mechanism of action of the medications has been well studied and hasessentially led to the death of tumor cells by apoptosis (Hannum Y A,Blood, 89:1845-1853). To avoid apoptosis, the cells use a category ofproteins encoded by genes called multidrug resistant genes (MDR) whichpermit them to control the intake or outflow of various molecules(Pastan I, Gottesman M M, 1991, Annu Rev Med, 42:277-286). In the caseof anti-cancer agents, these are actively evacuated by means ofP-glycoprotein (P-gp), produced by the MDR1 gene.

As all genes, the expression of the MDRs is controlled by differentnuclear factors. Thus, it has been recently shown that the MDR1 gene hasin its regulatory portion binding sites of the NF-κB factor (Zhou G, KuoM T, 1997, J Biol Chem, 272:15174-15183). This nuclear factor, whichmoreover plays a considerable role in numerous inflammatory situations(Barnes P J, Karin M, 1997, N Engl J Med, 336:1066-1071) participates inthe activation of the MDR1 gene.

Several recent works have established a connection between theinhibition and the activation of NF-κB and the potentialization ofapoptosis. In the first reported experiments (Wang C Y et coll., 1996,Science, 272:784-786, Van Antwerp D J et coll., Science, 272:787-789)the authors have validated their data by using genetically manipulatedlines to obtain the inhibition or the overexpression of NF-κB activity.Thus, this does not permit their direct use in therapeutic applications.

In another study, the authors have tested the effects of differentprotease inhibitors preventing the activation of NF-κB (pyrolidinedithiocarbamate, N-tosyl-L-lysl chloromethylcetone, N-acetyl cysteine)on a line of murine macrophages (Mannick E E et coll., 1997, Mediatorsof Inflammation, 6:225-232). The authors of this article conclude thereis a possible connection between NF-κB inhibition and the induction ofapoptosis of the inflammatory and immune cells.

Finally, another approach based on inhibition of the inflammatoryeffects of NF-κB, consists in overexpressing the natural inhibitor ofNF-κB, the IκB molecule, by gene therapy (Makarov S S et coll., 1997,Gene Ther, 4:846-852). This technology is also in the state ofdevelopment because of the complexity and the vectorization necessaryfor its good operation.

SUMMARY OF THE INVENTION

The present invention results from the discovery by the inventors of neweffects of the human growth hormone (HGH), also called somatotropin,namely, on the one hand that HGH, and other compounds connectedspecifically to the transmembrane receptors of class I cytokines, areinhibitors of the activation of NF-κB by a cytotoxic molecule, and, onthe other hand, that HGH, and other above-mentioned compounds, permitpotentiating the effects of cytotoxic molecules and hence reducing theconcentrations of these latter in the field of therapeutic treatments.

First of all, the inventors have observed that the human monocytesrespond less to a stimulation by lipopolysaccharides (LPS) when they arecultivated in the presence of exogenous recombinant HGH. The inventorshave accordingly concluded that HGH inhibits the activation of NF-κBafter stimulation by LPS (Haeffner A et coll., 1997, J Immunol,158:1310-1314).

Then, the inventors discovered that the human monocytes died afterbridging (or engagement) of the surface molecule AP01/CD95/Fas, and haveshown that HGH decreases the death mediated through the molecule Fas, byincreasing the synthesis of an antiapoptogenic proto-oncogene Bcl-2.

Finally, the inventors have studied the effects of HGH on the α-TNFresponse, because Fas and the p55 receptor of the α-TNF belong to thesame family of nerve growth receptors. The human promyeloid leukemicline U937 has been used to carry out this work, because of theinsensitivity of human monocytes to the death mediated by α-TNF.Obtaining results opposite those observed with Fas, namely that HGHaccelerates the death of these cells mediated by α-TNF, has permittedthe inventors to conclude as to the inhibitory effect of HGH on theactivation of NF-κB by α-TNF, or by other cytotoxic molecules activatingNF-κb, such as daunomycin.

OBJECTS OF THE INVENTION

Thus, the present invention has for its object to provide a new methodfor the treatment of cancers, and more particularly malignanthemopathies and solid tumors, offering the advantage of improving boththe response of the sick person to certain anti-cancer treatments andalso, potentially, the general condition of the sick person.

The invention also has for its object to provide new products for thetreatment of said pathologies, having both the advantage of increasingthe tumoral cell response to chemotherapy, and to improve the generalcondition of the patients. The new products of the invention permitdecreasing the activation of the NF-κB factor by means of the compoundthat is used to inhibit the activation of NF-κB, such as the humangrowth hormone, which is adapted to give rise to the inhibition of thetranscription of the MDR genes and hence a reinforcement of thecytotoxic effects of the anti-tumor agents used, with the expectedresult of decreasing the dosage of these anti-tumor medications.

The invention has for its object the use of compounds inhibiting theactivation of NF-κB, for the preparation of medications adapted for thetreatment of malign hemopathies and solid tumors.

The invention more particularly has for its object the use of NF-κBinhibitor compounds, for the preparation of medications for theprevention of the appearance or the treatment of phenomena of resistanceto cytotoxic molecules used in the field of treatment of theabove-mentioned pathologies, these resistance phenomena arising inpatients treated with these molecules when these latter are adapted toactivate NF-κB.

By compounds inhibiting the activation of NF-κB (also called NF-κBinhibitor compounds), there is meant any compound capable of inhibitingin the cells of the organism, the activation of NF-κB caused by thecytotoxic molecules used in the field of treatment of theabove-mentioned pathologies, and hence any compound capable ofinhibiting the synthesis of proteins (such as P-gp) permitting the cellsto eliminate the molecules before they can reach their moleculartargets.

The invention relates more particularly to the above-mentioned use ofcompounds inhibiting the activation of NF-κB, in association with one orseveral cytotoxic molecules usable in the field of treatment of malignhemopathies or solid tumors, said cytotoxic molecules being adapted toactivate the NF-κB factor.

Preferably, the compounds inhibiting the activation of NF-κB used in thescope of the present invention, are compounds binding specifically tothe transmembrane receptors of the cytokines of class I in the cells ofthe organism. Preferably, said compounds are selected from those bindingto the above-mentioned receptors whose amino acid sequences of thetransmembrane, intracytoplasmic and extramembrane portions have ahomology of about 50% to about 70%.

The invention has more particularly for its object the above-mentioneduse of compounds inhibiting the activation of NF-κB as defined above,selected from growth hormone, prolactin, erythropoietin, interleukin-4,interleukin-7, G-CSF, GM-CSF, interleukin-3, interleukin-6, of human orother mammal origin.

Preferably, said compounds are selected from growth hormone orerythropoietin.

In this connection the invention has more particularly for its objectthe above-mentioned use:

of human growth hormone, as obtained by extraction from hypophysaryextracts, and purification,

or, preferably, of the recombinant human growth hormone as encoded bythe nucleotide SEQ ID NO 1, or by any nucleotide sequence derived fromthis latter by degeneracy of the genetic code and being neverthelesscapable of encoding for the human growth hormone whose sequence in aminoacids is represented by SEQ ID NO 2, said growth hormone being obtainedby transformation of suitable cells with the help of vectors containinga nucleotide sequence such as described above, recovery of therecombinant protein produced by said cells, and purification.

The invention also relates to the above-mentioned use, of any peptidesequence derived by addition and/of deletion and/or substitution of oneor several amino acids of the sequence SEQ ID NO 2, and conserving theproperty of the human growth hormone of inhibiting the activation ofNF-κB.

The invention has more particularly for its further object theabove-mentioned use of recombinant human erythropoietin such as encodedby the nucleotide sequence SEQ ID NO 3, or by any nucleotide sequencederived from this latter by degeneracy of the genetic code and beingnevertheless capable of encoding for human erythropoietin, whosesequence in amino acids is represented by SEQ ID NO 4, saiderythropoietin being obtained by transformation of appropriate cellswith the aid of vectors containing a nucleotide sequence such asdescribed above, recovery of the recombinant protein produced by saidcells, and purification.

The invention also relates to the above-mentioned use, of any peptidesequence derived by addition and/or deletion and/or substitution of oneor several amino acids of the sequence SEQ ID NO 4, and preserving theproperty of human erythropoietin of inhibiting the activation of NF-κB.

The invention has more particularly for its object the above-mentioneduse of compounds inhibiting the activation of NF-κB as defined above,for the preparation of a medication administrable by the parenteralroute (IM, IV, SC), particularly in the amount of:

about 2 IU/kg of body weight/day in the case of human growth hormone,

of about 150 IU/kg of body weight/day in the case of humanerythropoietin.

Among the cytotoxic molecules adapted to activate the NF-κB factor usedin association with said compounds inhibiting the activation of NF-κBwithin the scope of the present invention, can be cited:

the cytokines,

the anthracyclines, of which may be mentioned daunomycin, anddauxorubicin,

the vinca-alkaloids, such as vinblastine and vincristin,

paclitaxel (or Taxol, DCI).

Preferably, the dosage of the cytotoxic molecules used in associationwith said compounds is about 2 to about 5 times less than the dosage ofthese same molecules used alone in the scope of the treatment ofmalignant hemopathies and solid tumors.

By way of illustration:

the usual daily dose of daunomycin or dauxorubicin being from 40 to 60mg/m², the dosage of these latter in the scope of the present inventionis about 5 to 30 mg/m²,

the usual daily dosage of vinblastine being from 5 to 7 mg/m², thedosage of this latter in the scope of the present invention is about 1to 4 mg/m²,

the usual daily dosage of vincristin being from 1 to 2 mg/m², the dosageof this latter in the scope of the present invention is about 0.1 to 1mg/m²,

the usual daily dosage of taxol being about 75 mg/m², the dosage of thislatter in the scope of the present invention is about 15 to 35 mg/m².

Among the cancers adapted to be treated in the scope of the presentinvention, can be cited principally:

malignant hemopathies such as leukemias, lymphomas,

solid tumors such as those of the ovary or the breast.

The invention also has for its object any product containing:

a compound inhibiting the activity of NF-κB such as described above, andmore particularly a compound binding specifically to the transmembranereceptors of the class I cytokines as defined above,

and a cytotoxic molecule adapted to activate the NF-κB factor,

as a combined preparation for simultaneous use, separate or prolongedover time, for the treatment of malignant hemopathies and solid tumors.

The invention also has for its object any product as defined above, as acombined preparation for simultaneous use, separate or over time, forthe prevention of the appearance, or for the treatment, of phenomena ofresistance to cytotoxic molecules used in the scope of treatment of theabove-mentioned pathologies, appearing in patients treated withmolecules when these latter are adapted to activate NF-κB.

The invention relates more particularly to any product as defined above,characterized in that it comprises as a compound inhibiting theactivation of NF-κB, growth hormone, prolactin, erythropoietin,interleukin-4, interleukin-7, G-CSF, GM-CSF, interleukin-3,interleukin-6.

Products particularly preferred in the scope of the present invention,are those comprising as a compound inhibiting the activation of NF-κB,growth hormone or erythropoietin.

The invention has more particularly for its object any product asdefined above, characterized in that it comprises:

human growth hormone obtained by extraction from hypophysary extracts,and purification,

or, preferably, recombinant human growth hormone as described above,encoded by the nucleotide sequence SEQ ID NO 1, or by any nucleotidesequence derived from this latter by degeneracy of the genetic code andbeing nevertheless capable of encoding for the human growth hormonewhose sequence of amino acids is represented by SEQ ID NO 2, or anypeptide sequence derived by addition and/or deletion and/or substitutionof one or several amino acids of the sequence SEQ ID NO 2, andpreserving the property of human growth hormone to inhibit theactivation of NF-κB.

The invention also has for its object any product as defined above,characterized in that it comprises recombinant human erythropoietin suchas described above encoded by the nucleotide sequence SEQ ID NO 3, or byany nucleotide sequence derived from this latter by degeneracy of thegenetic code and being nevertheless capable of encoding for humanerythropoietin whose sequence in amino acids is represented by SEQ ID NO4, or any peptide sequence derived by addition and/or deletion and/orsubstitution of one or several amino acids of the sequence SEQ ID NO 4,and preserving the property of human erythropoietin to inhibit theactivation of NF-κB.

The invention also relates to any product as described above,characterized in that it comprises as cytotoxic molecule adapted toactivate the NF-κB factor, any molecule selected from the following:

cytokines,

anthracyclines, such as daunomycin or dauxorubicin,

vinca-alkaloids, such as vinblastine and vincristine,

paclitaxel (or Taxol, DCI).

Products such as those defined above that are preferred in the scope ofthe present invention, are characterized in that they contain:

growth hormone and daunomycin or dauxorubicin, in proportions such thattheir daily dosage is about 2 IU/kg of growth hormone for about 5 to 30mg/m² of daunomycin or dauxorubicin,

growth hormone and vinblastine, in proportions such that their dailydosage is about 2 IU/kg of growth hormone for about 1 to 4 mg/m² ofvinblastine,

growth hormone and vincristine, in proportions such that their dailydosage is about 2 IU/kg of growth hormone for about 0.1 to 1 mg/m² ofvincristine,

growth hormone and taxol, in proportions such that their daily dosage isabout 2 IU/kg of growth hormone for about 15 to 35 mg/m² of taxol,

erythropoietin and daunomycin or dauxorubicin, in proportions such thattheir daily dosage is about 150 IU/kg of erythropoietin for about 5 to 3mg/m² of daunomycin or dauxorubicin,

erythropoietin and vinblastine, in proportions such that their dailydosage is about 150 IU/kg of erythropoietin for about 1 to 4 mg/m² ofvinblastine,

erythropoietin and vincristine, in proportions such that their dailydosage is about 150 IU/kg of erythropoietin for about 0.1 to 1 mg/m² ofvincristine,

erythropoietin and taxol, in proportions such that their daily dosage isabout 150 IU/kg of erythropoietin for about 15 to 35 mg/m² of taxol.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1: The effect of growth hormone on the mortality of cells exposedto α-TNF: the percentage of the dead cells (IP+) is indicated on theordinate, the white colonies corresponding to the cells of the strainU937-Neo, the black colonies corresponding to the cells of the strainU937-hGH; the concentrations of NFT-α are indicated on the abscissa inIU/ml.

FIG. 2: The effect of growth hormone on the translocation of NF-κB;column 1 corresponds to the control cells U937, column 2 corresponds tothe U937 cells treated with α-TNF+cycloheximide, column 3 corresponds tothe U937 cells treated with α-TNF, column 4 corresponds to the U937cells treated with α-TNF+a mutant NF-κB probe, column 5 corresponds tothe U937 cells treated with α-TNF+a homologous NF-κB probe, column 6corresponds to the control cells U937-HGH, column 7 corresponds to theU937-HGH cells treated with α-TNF+cycloheximide, column 8 corresponds tothe U937-HGH cells treated with α-TNF; the presence of NF-κB isindicated by an arrow.

FIG. 3: Effect of growth hormone on the reporter activity CAT; thepercentage of variation of CAT activity is indicated on the abscissa;the two left columns show the two experiments carried out on U937-Neocells, and the two right columns represent the two independentexperiments carried out on U937-HGH cells.

FIG. 4: Effect of growth hormone on apoptosis induced by daunomycin; thepercentage of the dead cells (IP+) is indicated on the ordinate, thewhite columns corresponding to the cells of the strain U937-Neo, theblack columns corresponding to the cells of the strain U937-HGH; theindicated percentages show the increase of mortality of the cells; theconcentrations of daunomycin are indicated on the abscissa in μM.

FIG. 5: Effect of growth hormone on the apoptosis of the IGROV/ADR line,induced by daunomycin; the percentage of dead cells (IP+) is indicatedon the ordinate, and different columns corresponding to the differentconcentrations of HGH used (0, 5, 50, 500, 1000 ng/ml); theconcentrations of daunomycin are indicated on the abscissa in μM.

FIG. 6: Effect of erythropoietin on the apoptosis of the human renalcarcinoma line HIEG, induced by daunomycin: for each of the experiments1 and 2, the number of living cells is indicated on the ordinate, thewhite columns correspond to the RCC-Neo cells, the black columnscorrespond to the RCC-EPO cells; the concentrations of daunomycin areindicated on the abscissa in μM.

DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS

The invention is illustrated with the help of the following detaileddescription of the in vitro effect of growth hormone and erythropoietinon tumoral cell lines.

1) EXAMPLE NO. 1

A selection gene (neomycin resistant, NeOR) and the gene encoding forhuman growth hormone (HGH) have been co-transfected in the humanpromyeloid leukemic line U937. By comparing the transfected lineU937-HGH (which produces in a constituent fashion HGH at physiologicdoses), either to the parent line U937, or to a line transfected withNeo^(R) alone, there are observed by different methodologicalapproaches, that the U937-HGH line dies more under the effect of thetumor necrosis factor (α-TNF). This cytokine secreted by different typesof immune cells has an anti-tumor activity (Harakana, K et al., 1984,Int J Cancer, 34:263-267) and is capable of promoting the activation ofNF-κB (Baeuerle P A, Henkel T, 1994, Ann Rev Immunol, 12:141-179).

The U937-HGH cells and the U937-Neo control cells have been cultured for48 hours in the presence of increasing concentrations of recombinantα-TNF. As a result of this culture, the washed cells have been incubatedin the presence of propidium iodide which is incorporated in the DNA ofthe dead cells. These cells are analyzed by flowing cytometry.

FIG. 1 shows the increase of the incorporation of propidium iodide as afunction of increasing doses of α-TNF expressed in international units(IU). For the U937 cells (the mother line having served to obtain theU937-HGH lines), with increase of the concentration of α-TNF, there isobserved a slight increase of the percentage of fluorescent cells (thusdead) due to the incorporation of propidium iodide (red fluorescence).This figure shows on the other hand clearly the fact that these valuesare much higher for the U937-HGH line, as a function of increasing dosesof α-TNF added to the same culture.

It is thus demonstrated that the presence in the cellular cultures ofHGH produced by the U937 lines transfected with the HGH gene, increasestheir susceptibility to the induction of death mediated by α-TNF.

2) EXAMPLE NO. 2

Having reported in a previous study that HGH could intervene in theinhibition of the activation of NF-κB mediated by lipopolysaccharides(Haeffner A et coll., 1997, J Immunol, 158:1310-1314), the inventorshave studied the status of NF-κB during stimulation of the differentlines by α-TNF.

FIG. 2 shows the result of an analysis by gel delay. On this gel weredeposited nuclear extracts from the U937-HGH and U937 cells (the motherline having served for obtaining the U937-HGH lines) subjected todifferent inductors including α-TNF or α-TNF and cycloheximide(inhibitor of protein synthesis). This experiment indicates clearly thatthe presence of NF-κB in the nuclei of the U937-HGH cells, is decreasedrelative to the control cells.

The presence of NF-κB is seen in lines 4 and 5, which represent themigration of the nuclear extracts of U937 cells stimulated by α-TNF, andpre-incubated, either with a cold probe muted NF-κB which does notdisplace the signal (line 4), or with a cold probe NF-κB homolog whichinhibits the signal (line 5).

FIG. 3 shows the result of an enzyme immunoassay (ELISA) carried outwith the lysate of U937-HGH and U937-Neo cells transfected in atransitory manner with a plasmid containing NF-κB sequences in thepromotor of the reporter gene encoding forchloramphenicol-acetyl-transferase (CAT) (Chiao P et coll., 1994, ProcNatl Acad Sci USA, 91:28-32).

The cells are transfected by electroporation then incubated with α-TNF.At the end of culturing, the cells are lysated and the activated CAT ismeasured by an commercial ELISA (Boehringer-Mannheim) according to thedirections of the supplier.

The figure shows that the CAT activity, reflected by the presence ofNF-κB, is decreased in the U937-HGH cells relative to the control cells,after stimulation by α-TNF.

The results shown in FIGS. 2 and 3 therefore show by two differentmethodological approaches, that the synthesis of NF-κB is decreased inU937-HGH relative to the control line.

3) EXAMPLE NO. 3

The use of α-TNF being very difficult in human clinical work because ofthe adverse side effects, the inventors are interested in daunomycin.This anthracyclin used in anti-cancer therapy under the name ofCerubidine□ acts by insertion in the cellular DNA sequences, thusdisturbing the cellular function. Like α-TNF (Baeuerle P A, Henkel T,1994, Ann Rev Immunol, 12:141-179), daunomycin activates NF-κB (Das K C,White C W, 1997, J Biol Chem, 272:14914-14920).

FIG. 4 indicates that the U937-HGH line is also more sensitive than thecontrol line to the mediated death by daunomycin.

4) EXAMPLE 4

To test the possibility of using the object of the present invention onnon-lymphoid tumors, the inventors have used HGH to try to invert the“adriamycine resistant” pheno-type of cells isolated from a humanovarian adenocarcinoma IGROV/ADR (Benard J et coll., 1985, Cancer Res,45:4970-4979).

As shown by FIG. 5, these cells are insensitive to the toxic effect ofthe daunomycin added to the culture (HGH groups 0 ng/ml). The additionof recombinant HGH (Saizen□, Serono laboratory) renders these cellssensitive to daunomycin, with a maximum effect observed for the lowestdose of HGH used here, namely 5 ml/ml.

These result proves on the one hand that the results of aggravatedmortality can be obtained as well with recombinant exogenous HGH as withthe transfected lines mentioned above, and that on the other hand, thepresent invention can be applied to non-lymphoid solid tumors.

5) EXAMPLE NO. 5

Erythropoietin (EPO), another molecule than HGH belonging to the samefamily of cytokines of class I, has been tested on human renal carcinomacells (RCC) HIEG.

4.10⁴ RCC cells have been transfected in a transitory manner with thehelp of an Effecten□ kit, or with 3 μg of plasmid carrying the geneencoding for EPO (RCC-EPO cells), or with 3 μg of a plasmid coding forthe resistance to neomycin (RCC-Neo cells) as the negative control.After 48 hours, the RCC were combined with daunomycin at two differentconcentrations: 0.3 and 0.6 μM. The number of surviving cells wasmeasured 48 hours later by flow cytometry (FIG. 6).

The results of Experiment 1 expressed in numbers of living cells are asfollows: RCC-Neo RCC-EPO daunomycin 0 μM 14745 26911 daunomycin 0.3 μM11382 3487 daunomycin 0.6 μM 10179 8551

The results of Experiment 2 expressed in numbers of living cells are asfollows: RCC-Neo RCC-EPO daunomycin 0 μM 20150 29102 daunomycin 0.3 μM8891 2693 daunomycin 0.6 μM 7001 4739

The results show that in the two different experiments (Experiments 1and 2), the conjoint presence of daunomycin and EPO aggravatessubstantially the cellular mortality, with a more marked effect for thelower dose of daunomycin used.

1. A method treating a patient having or subject to developing malignanthemopathies or solid tumors and/or to treat resistance to cytotoxicmolecules of said treatments, comprising administering an effectiveamount of a compound that inhibits the activation of the nuclear factorκB (NF-κB).
 2. The method according to claim 1, further comprising oneor several cytotoxic molecules usable in the scope of treatment of theabove-mentioned pathologies and adapted to activate the NF-κB factor. 3.The method according to claim 2, wherein said compounds inhibiting theactivation of MF-κB are connected specifically to the transmembranalreceptors of the cytokins of class I in the cells of the organism. 4.The method according to claim 1, wherein said compound is a recombinanthuman erythropoietin such as encoded by the nucleotide sequence SEQ IDNO 3, or by any nucleotide sequence derived from this latter bydegeneracy of the genetic code and being nevertheless capable ofencoding for human erythropoietin whose sequence in amino acids isrepresented by SEQ ID NO 4, said erythropoietin being obtained bytransformation of appropriate cells with the help of vectors containedin a nucleotide sequence as described above, recovery of the recombinantprotein produced by said cells, and purification; or any peptidesequence derived by addition and/or deletion and/or substitution of oneor several amino acids of the sequence SEQ ID NO 4, and preserving theproperty of inhibiting the activation of NF-κB.
 5. The method accordingto claim 1, wherein said compounds are in combination with one orseveral cytotoxic molecules adapted to activate the NF-κB factor,selected from: cytokines, anthracyclines, including daunomycin, anddauxorubicin, vinca-alkaloids, such as vinblastine and vincristine,paclitaxel (or Taxel, DCI).
 6. The method according to claim 1, saidcompound is administered with a dosage of the cytotoxic molecules usedin combination with said compounds in about 2 to about 5 times less thanthe dosage of these same molecules used alone in the scope of treatmentof malignant hemopathies and solid tumors.